Computer security compromised by hardware failure: Difference between revisions

Revision as of 15:51, 4 February 2015

Revision as of 15:57, 4 February 2015

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===== The Falling Edge Transition Technique =====

When a key is pressed, released or held down, the keyboard sends a packet of information known as a scan code to the computer.<ref name="Vuag3">[[#Vuag1|Vuagnoux, 2009, p.5]]</ref> The protocol used to transmit these scan codes is a bidirectional serial communication, based on four wires: Vcc (5 volts), ground, data and clock.<ref name="Vuag3"/> Clock and data signals are identically generated. Hence, the compromising emanation detected is the combination of both signals. However, the edges of the data and the clock lines are not superposed. Thus, they can be easily separated to obtain independent signals.<ref name="Vuag4">[[#Vuag1|Vuagnoux, 2009, p.6]]</ref>how would it be if it has no egd.

===== The Generalized Transition Technique =====